Laparoscopic and endoscopic surgical procedures are minimally invasive procedures in which operations are carried out within the body by means of elongated instruments inserted through small entrance openings in the body. These procedures are less invasive leading to reduced surgical trauma, lower costs and quicker recovery times than conventional surgery. However this requires that the surgeon operate in narrow spaces with small areas for maneuvering and with limited visibility using endoscopes.
In these procedures often portions of tissue must be sealed, dissected or sealed and dissected as part of the procedure. When this is performed inside body cavities having narrow operating areas this tissue manipulation can be difficult. Conventional sealing and dissecting instruments utilized in most of these procedures are forward facing cutting instruments such as scissors, blades or bipolar or single polar electrodes. These types of cutters are best utilized with an off axis endoscope so that the cutting head of the instrument is visible throughout the procedure. However if the cutting instrument is placed through the working channel of the endoscope or alongside the endoscope, the actions of a forward facing cutter are not always visible. The lack of visibility can result in less precise tissue dissection and the added risk of tissue dissection that is undesired. Additionally some areas of tissue removal cannot be approached with a forward cutting device. The surgeon must either work awkwardly with a forward cutting instrument or create an instrument portal close to the viewing portal which can make triangulation of the work awkward and difficult.
Therefore a reverse acting sealing and cutting device would be advantageous that will operate in a manner such that the surgeon can easily visualize the operational area without the cutting head obstructing the endoscopic view. This type of cutter should have a simple sealing and cutting mechanism and should be easily activated by the surgeon from outside the patient. Other reverse acting cutters have been previously described such as that described by Auerbach (U.S. Pat. No. 5,649,947) and others but these are primarily cutters and graspers only. These do not describe the need to seal tissue before cutting so that body channels are sealed off and body fluids such as blood vessels contained. Furthermore these described cutters utilize cams and long cable and rod actuators that are cumbersome, bulky and mechanically complex to operate and manufacture. A need exists therefore for improved instruments for sealing and dissecting tissue inside the body that utilize a reverse acting activation head. Additionally a need exists for an improved device for sealing tissue before cutting the tissue. Finally there exists a need for a simple to operate reverse acting cutter that utilizes a simple mechanical mechanism for effectively removing body tissue.